Double seaming chuck-knockout

ABSTRACT

A chuck-knockout assembly for seaming a can end onto a can body to form a seamed container is disclosed. The chuck-knockout assembly may include an upper chuck body and a lower chuck body. The upper chuck body may include a first drive surface and may be rotatably coupled to a seaming machine frame. The lower chuck body may include a second drive surface and may be longitudinally moveable relative to the upper chuck body. The second drive surface may be configured to engage a periphery of the can end during seaming and disengagement of the container.

TECHNICAL FIELD

The present technology relates to manufacturing of metal packaging. Moreparticularly, the invention relates to an apparatus and methods forassembling a container and can end.

BACKGROUND

In the field of metal packaging, typical containers are sealed byseaming a can end onto a can body using the well-known double seamingprocess. The double seaming process is typically performed on a seamingmachine having a plurality of forming stations. Each station contains arotatable seaming chuck that acts as an anvil to support the can endwhile two rotatable seaming rolls are brought into contact with thecontainer using a cam motion. The two seaming rolls define specificgroove geometries that are configured to form a portion of the can bodyand a portion of the can end into a commercially acceptable double seam.

A can body is typically raised into engagement with a forming stationusing a lifter plate or other positioning mechanism. After the doubleseam is formed and the positioning mechanism is retracted, the sealedcontainer is ejected from the station so the seam-forming cycle can berepeated on another container. Typically, ejection of the seamedcontainer may be achieved by the use of a knockout rod or pad that tapsthe center of the container to knock the container out of engagement theseaming chuck.

A trend in beverage cans has been toward reduced end diameters. Further,many conventional beverage can ends have a small center panel diameterrelative to a seaming panel or peripheral curl diameter. For example,U.S. Pat. Nos. 6,065,634, 6,702,142, 6,516,968 and 7,350,392, each ofwhich is incorporated by reference in its entirety, disclose beveragecan ends having a relatively small center panel because the chuck wallis inclined (as measured from an upper point to a lower point of thechuck wall).

The conventional design of knockout pad and seaming chuck is such thatthe seaming chuck locates the can end. Thus, conventional knockout padstypically fit inside the diameter of the surface of the chuck thatcontacts the can end, which leaves a certain amount of radial movementbetween the can end and the knockout prior to engagement with theseaming chuck. With certain end designs (i.e. lightweight ends) thecountersink is moved inboard and with the traditional design ofknockout, the radial movement available to the can end prior toengagement with the seaming chuck is increased. This radial movement isa result of the knockout not having a feature that locates and controlsthe end concentric with the rotatable seaming chuck. With this radialmovement comes the opportunity for misalignment on assembly with theseaming chuck (during what's called the transition zone) which may causecollapse, creases and poor seam quality.

Furthermore, after conventional knockouts have located a can end, theload applied to the can end decreases to zero during the transitionzone. Therefore, by the time the can body and can end engage the chuck,the can end and can body combination could be misaligned to the chuck,thereby causing damage to the can bodies and can ends. To preventdamage, often times certain seamers have to run at slower speeds such asless than 1500 cans/minute.

Accordingly, there is a need for an improved apparatus and method forlocating and seaming a can end onto a can body.

SUMMARY

A chuck-knockout assembly that (among other things) gives improvedlocation of a can end during the seaming operation (i.e. at least duringthe transition zone). Such improvements may be achieved by utilizingsome or all of the features of the chuck-knockout assemblies describedbelow.

In one embodiment, a chuck-knockout assembly for seaming a can end ontoa can body to form a seamed container may include an upper chuck bodyand a lower chuck body. The upper chuck body may include a first drivesurface. The first drive surface may at least partially define a seamingsurface for contacting a portion of the can end during seaming andagainst which a seaming force is applied. The lower chuck body islongitudinally moveable relative to the upper chuck body and includes asecond drive surface. The second drive surface may be located outboardof a periphery of a center panel of the can end. The second drivesurface may be capable of locating the can end prior to seaming, may becapable of maintaining the can end during seaming and may also becapable of contacting the can end to disengage the can end from thechuck-knockout assembly after seaming.

The second drive surface of the lower chuck body may be configured toengage a countersink of the can end. Furthermore, the can end maycomprise a pull tab, and the lower chuck body may be configured to bedevoid of contact with the pull tab during the seaming and release.

A seaming system for seaming and release of a container including a canend and a can body is also provided. The seaming system may comprise achuck-knockout assembly and first and second seaming rolls. Thechuck-knockout assembly may include an upper chuck body and a lowerchuck body. The upper chuck body may include a first drive surface, andmay be rotatably coupled to a seaming machine frame. The lower chuckbody may include a second drive surface, and may be longitudinallymoveable relative to the upper chuck body. The first and second seamingrolls may be configured to form a seam on the container between the canend and the can body. The first drive surface and the second drivesurface may define a seaming surface when the seam is being formed. Thesecond drive surface may contact an outer periphery of the can endduring release of the container from the chuck-knockout assembly.

A method of seaming a container including a can end and a can body isalso disclosed. The method may comprise the steps of (1) providing achuck-knockout assembly comprising an upper chuck body and a lower chuckbody; (2) locating a can end from an infeed mechanism onto thechuck-knockout assembly such that a second drive surface of the lowerchuck body is in contact with a periphery of the can end; (3) seamingthe can end to a can body to form a container while the second drivesurface is in contact with the periphery of the can end; and (4)releasing the container from the chuck-knockout assembly by moving thelower chuck body longitudinally relative to the upper chuck body, thelower chuck body moving from a seaming position to a knockout position,wherein the second drive surface is in contact with the periphery of thecan end as the lower chuck body is moving to the knockout position.

In another embodiment a chuck-knockout assembly may utilize a vacuumforce to locate the can end. For example, a chuck-knockout assembly mayinclude a chuck body having an aperture and a first drive surface thatat least partially defines a seaming surface for contacting a portion ofthe can end during seaming and against which a seaming force may beapplied. A vacuum force may be applied through the aperture to locatethe can end onto the chuck body prior to seaming and may hold the canend during seaming.

By using chuck-knockout assemblies that provide improved location of canends certain seamers may be operated at higher speeds. The improvedlocation may among other things be as a result of sufficient loads beingapplied to the can end and can body combinations during at least amajority of the transition zone. Therefore a method of seaming a can endonto a can body to form a container, may include (1) positioning the canend on top of the can body; (2) lifting the can body and can endcombination with a lifter plate; (3) locating the can end with achuck-knockout assembly such that the can body and can end combinationis between the lifter plate and the chuck-knockout assembly; (4)maintaining a load that is between 15 and 100 lbf on the can body andcan end combination for at least part of the transition zone; and (5)seaming the can end onto the can body during a first seaming operation.Preferably the load in the transition zone is maintained between about30 lbf and about 38 lbf and even more preferably at about 35 lbf.

These and various other advantages and features are pointed out withparticularity in the claims annexed hereto and forming a part hereof.However, for a better understanding of the invention, its advantages,and the objects obtained by its use, reference should be made to thedrawings which form a further part hereof, and to the accompanyingdescriptive matter, in which there are illustrated and describedpreferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side cross-sectional view of a seaming system seaming a canend onto a can body;

FIG. 2 is a schematic showing a seaming operation;

FIG. 3A is a side cross-sectional view of a chuck-knockout assemblycapable of being used in the system depicted in FIG. 1;

FIG. 3B is a side cross-sectional view of the chuck-knockout assemblydepicted in FIG. 3A in a knockout position;

FIG. 4A is a partial side cross-sectional view of a seaming system withthe chuck-knockout assembly in the seaming position as depicted in FIG.3A;

FIG. 4B is a partial side cross-sectional view of a seaming system withthe chuck-knockout assembly in the knockout position as depicted in FIG.3B;

FIG. 5 is a side view of a cam for actuating a knockout;

FIG. 6 is a graph showing the loads applied to a can end during at leasta transition stage of the seaming operation; and

FIG. 7 is a side cross-sectional view of another chuck-knockout assemblycapable of being used in the system depicted in FIG. 1.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Preferred structures and methods for container seaming technology aredescribed herein. An embodiment of a seaming system and chuck-knockoutassembly that employ this technology are also described. The presentinvention is not limited to any particular seaming configuration butrather encompasses use in any container seaming application. Further,the present invention encompasses other seaming system and containerdesigns not described herein.

Referring to FIG. 1, a seaming system 10 includes a seaming machineframe 11, a chuck-knockout assembly 12 (including a knockout and achuck), a first seaming roll 14, and a second seaming roll 15. Seamingmachine frame 11 includes a shaft 13 for rotating chuck-knockoutassembly 12 and a lifter plate 16 for lifting a container 20 containinga product 23 into engagement with chuck-knockout assembly 12.Chuck-knockout assembly 12 is affixed to shaft 13 and rotatably coupledto seaming machine frame 11. First seaming roll 14 and second seamingroll 15 are configured to form a double seam 24 in container 20 thatseals a can end 26 onto a can body 28 via a seaming process that isknown in the art (e.g., bending a curl portion of can end 26 around thetop edge of can body 28).

FIG. 2 is a schematic showing the seaming operation. First, a can bodyand can end enter the seamer at point A. At point B which may beapproximately 1 degree from point A, the can body picks up the can end.At this point, the knockout makes contact with and locates the can endand can body combination. From point B to point C is known as thetransition zone. The can end engages the chuck at point C which is about24.5 degrees from point A. At point D, which is about 27 degrees frompoint A the first seaming operation begins and at point E, which isabout 148 degrees from point A the second seaming operation begins. Thecan body and can end combination is then discharged at point F which isabout 218 degrees from point A.

During the seaming operations, chuck-knockout assembly 12 may be rotatedby shaft 13 or a seaming head or spindle (not shown) attached to shaft13 about an axis indicated by arrow Y in FIG. 1. First seaming roll 14and second seaming roll 15 may be brought into contact with container 20(typically using a cam motion), and first seaming roll 14 and secondseaming roll 15 may be rotated about an axis also indicated by arrow Y.Chuck-knockout assembly 12 may support one or more surfaces of can end26 while first seaming roll 14 and second seaming roll 15 apply a force(generally directed radially inward) to container 20 to form double seam24.

After seaming, lifter plate 16 may be lowered, and a portion ofchuck-knockout assembly 12 may push against can end 26 to eject orrelease container 20 from chuck-knockout assembly 12. The seaming cyclemay then be repeated to form double seam 24 on another container 20.

Seaming system 10 may typically form a double seam 24 on a variety oftypes of containers 20. A typical container 20 may contain or beconfigured to contain product 23, including a beverage, ready meals,fruits, vegetables, fish, dairy, pet food, or any other product that itis desirable to store in metal packaging such as container 20. Container20 may have any length, diameter, wall thickness, and volume. Container20 typically has a standard-sized interior volume that is known in theart for containing product 23 such as a beverage, ready meals, fruits,vegetables, fish, dairy, or pet food.

Container 20, including can end 26 and a can body 28 may be made fromany material, for example, steel, aluminum, or tin plate. Can end 26 mayinclude an approximately planar panel that may be formed, pressed,and/or stamped to take a shape that may include several features. Canend 26 may include an openable panel portion (not shown) that extendsover a portion or most of can end 26, and the openable panel may beopened by breaking a score (not shown) to create an aperture (not shown)through which a user may remove product 23. Can end 26 may include apull tab (not shown) to allow a user to open the openable panel portionto remove product 23.

Referring now to FIGS. 3A and 3B, a chuck-knockout assembly 12 a may beused in a seaming system such as seaming system 10 (shown in FIG. 1). Asshown, chuck-knockout assembly 12 a includes an upper chuck body 30 anda lower chuck body 34. Upper chuck body 30 and lower chuck body 34together at least partially define a seaming surface 38 during seamingof an end onto a container. Lower chuck body 34 also helps locate andmaintain the can end prior to seaming of the can end onto the can body(i.e. during the transition zone shown in FIG. 2) and may eject orrelease the can end from the chuck-knockout assembly 12 a after seaming.Chuck-knockout assembly 12 a defines a longitudinal axis Y.

As shown in FIGS. 3A and 3B, upper chuck body 30 includes a first drivesurface 42 that partially defines seaming surface 38. As shown, firstdrive surface 42 is approximately vertical. Upper chuck body 30 alsodefines one or more retainer cavities 46 that may be coupled to one ormore retainers or protrusions (not shown) extending from shaft 13 or aseaming head or spindle (not shown) to affix chuck-knockout assembly 12a to shaft 13. In other embodiments, any other retention mechanism thatis known in the art may be used to affix chuck-knockout assembly 12 a toshaft 13. Upper chuck body 30 mates with lower chuck body 34 along anouter mating surface 50 and an inner mating surface 54.

Upper chuck body 30 may be made from any material, for example, steel oriron. Upper chuck body 30 preferably has a generally cylindrical outershape, centered around longitudinal axis Y. Upper chuck body 30 mayinclude an internal void (not shown) that may be configured to allow aportion of a knockout rod assembly 58 to pass through upper chuck body30 and be affixed to lower chuck body 34.

Lower chuck body 34 includes a second drive surface 62 that may servemultiple purposes. For example, second drive surface 62 partiallydefines seaming surface 38 during the seaming operation. Second drivesurface 62 may also locate the can end prior to the seaming operationand may serve to push against the can end to disengage or release asealed container from chuck-knockout assembly 12 a after seaming. Seconddrive surface 62 preferably has a cylindrical or frusto-conical shapethat may be configured to mate with corresponding peripheral features ofthe can end (as shown, for example, in FIGS. 4A and 4B). As shown, aportion of second drive surface 62 may extend into a countersink of thecan end. Lower chuck body 34 also defines a central cavity 66 that mayallow one or more radially inward features of the can end (e.g., a lifttab, a score, or an openable panel portion) to be devoid of contact withchuck-knockout assembly 12 a during and after seaming). In this regard,the upper surface that forms cavity 66 preferably is spaced apart fromthe can end.

Lower chuck body 34 may be made from any material, for example, steel oriron, and may be coated or surface treated. Lower chuck body 34preferably has a generally cylindrical outer shape, centered aroundlongitudinal axis Y. Lower chuck body 34 may be coupled to knockout rodassembly 58 (preferably cam-actuated) which may pass through aperturesin upper chuck body 30 and shaft 13 and may be coupled to seamingmachine frame 11 (shown in FIG. 1).

As shown in FIGS. 3A and 3B, lower chuck body 34 may be slideable alonglongitudinal axis Y relative to upper chuck body 30 between a seamingposition and a knockout position. Lower chuck body 34 may besubstantially angularly fixed relative to upper chuck body 30 in boththe seaming position and the knockout position. Lower chuck body 34 mayhave a substantially constant angular position about longitudinal axis Yrelative to upper chuck body 30, such that upper chuck body 30 and lowerchuck body 34 may rotate together about longitudinal axis Y (e.g.,during seaming). To permit lower chuck body 34 to be slideable relativeto upper chuck body 30 only along longitudinal axis Y, mating verticalcorrugations or splines (not shown) may be provided in the outer surfaceof lower chuck body 34 and the inner surface of upper chuck body 30.Lower chuck body 34 may be actuated along longitudinal axis Y by themotion of knockout rod assembly 58, which preferably is cam-actuated.

When lower chuck body 34 is in the seaming position, as shown in FIG.3A, an outer mating surface 70 of lower chuck body 34 may be in contactwith or disposed proximate to corresponding outer mating surface 50 ofupper chuck body 30, and an inner mating surface 74 of lower chuck body34 may be in contact with or disposed proximate to corresponding innermating surface 54 of upper chuck body 30.

When lower chuck body 34 is in the knockout position, as shown in FIG.3B, outer mating surface 70 of lower chuck body 34 may be spaced apartfrom outer mating surface 50 of upper chuck body 30, creating an outerseparation gap A, and inner mating surface 74 of lower chuck body 34 maybe spaced apart from inner mating surface 54 of upper chuck body 30,creating an inner separation gap B. The distance that surfaces 50 and 70and that surfaces 54 and 74 are spaced apart may be chosen by personfamiliar with seaming technology according to well-known principles uponconsideration of this disclosure.

Referring now to FIGS. 4A and 4B, chuck-knockout assembly 12 a may beconfigured to engage and support corresponding features on a can end 78during the seaming operation. For example, while in the knockoutposition lower chuck body 34 locates can end 78 by having second drivesurface 62 engage the outer periphery (i.e., at least one of a chuckwall 86, a countersink 90, or a peripheral portion of an approximatelyplanar center panel of can end 78 located near countersink 90 butradially outside of a pull tab or tear panel) of can end 78. Lower chuckbody 34 then moves to a seaming position so that the end 78 may beseamed onto a can body 82. As shown in FIG. 4A first drive surface 42and second drive surface 62 together define seaming surface 38 whenlower chuck body 34 is in the seaming position. During seaming, seamingsurface 38 serves as an anvil to support a portion of chuck wall 86 ofcan end 78 against the generally inwardly-directed force applied by afirst seaming roll (not shown) and a second seaming roll 92 to form adouble seam 94.

As a result of the seaming process, chuck wall 86 may exert a retentionforce (generally directed radially inward) on seaming surface 38. Also,a portion of chuck wall 86 may be partially bent around the upper cornerof seaming surface 38 (i.e., can end cut-over), thereby increasing anyretention force that chuck wall 86 may be exerting on seaming surface38.

After seaming, as shown in FIG. 4A, and subsequent lowering of thelifter plate (i.e. lifter plate 16 shown in FIG. 1), lower chuck body 34moves from its retracted position of FIG. 4A to the extended or knockoutposition as shown in FIG. 4B. As lower chuck body 34 moves to theknockout position the container may be ejected from chuck-knockoutassembly 12 a. To eject the container, lower chuck body 34 may be moveddownward relative to upper chuck body 30, along longitudinal axis Y.Lower chuck body 34 may be moved downward by knockout rod assembly 58,which may slide through a void inside upper chuck body 30.

As lower chuck body 34 begins to move down, lower chuck body 34 mayexert an ejection force on the container via second drive surface 62.Second drive surface 62 preferably pushes downward on a periphery of canend 78. The presence of cavity 66 may allow second drive surface 62 topush down on the periphery of can end 78 while being devoid of contactwith one or more radially inward features of can end 78 (e.g., a lifttab, a score, or an openable panel portion). The openable panel portion,score, and/or pull tab may penetrate into cavity 66 without contactinglower chuck body 34.

As lower chuck body 34 continues to move down, the separation of outermating surfaces 50 and 70 may begin to create outer separation gap A,and the separation of inner mating surfaces 54 and 74 may begin tocreate inner separation gap B. Lower chuck body 34 continues to movedown until separation gap A is large enough that the retention forcethat a portion of chuck wall 86 exerts on seaming surface 38 becomesless than the gravitational force acting to pull the container off ofchuck-knockout assembly 12 a, at which point container 20 disengagesfrom knockout assembly 12 a. In some embodiments, lower chuck body 34may continue to move down until separation gap A is greater than theheight of double seam 94, thereby eliminating contact between chuck wall86 and seaming surface 38 and enhancing disengagement or release of thecontainer from chuck-knockout assembly 12 a.

While not being bound by theory, it is believed that the improvedaligning of second drive surface 62 with a periphery of can end 78,compared with using a conventional knockout rod, pin, or pad, may allowfor a more controlled can handling, which may reduce seaming processtime and reduce potential damage to seamed containers. For example,having an increased controllability of the can end while the can end isbeing located and increased stability of the container during ejectionfrom chuck-knockout assembly 12 a may help prevent the container fromcrushing or creasing during and after the seaming operation.

In this regard, after a container 20 is ejected from chuck-knockoutassembly 12 a, lower chuck body 34 preferably contacts and locatesanother, incoming can end while lower chuck body 34 is in the extended,knockout position. Lower chuck body 34 then moves upwards relative toupper chuck body 30 along longitudinal axis Y, reestablishing contactbetween outer mating surfaces 50 and 70 and inner mating surfaces 54 and74 and eliminating the separation gaps A and B. When chuck-knockoutassembly 12 a has returned to the seaming position, the double seamingprocess may be repeated, whereby a double seam may be created on a newcontainer.

Lower chuck body may be actuated using a cam. As the lower chuck body isactuated in a downward direction, and once the lower chuck body haslocated a can end, a vertical load may be applied to the can end tothereby hold the can end onto the can body. Preferably the load remainssufficient at least during the transition zone, as explained more fullybelow. FIG. 5 shows an example cam that may be used to actuate the lowerchuck body. As shown, a cam 120 includes a path 124. As thechuck-knockout completes an operation, the cam profile will cause thelower chuck body to actuate.

By using a chuck-knockout assembly having some or all of the featuresdescribed, a sufficient compressive load may be applied to the can endand can body combination during at least a majority of the transitionzone of the seaming operation. Preferably the compressive load isapplied during the entire transition zone. FIG. 6 is a graph that showsthe loads applied to the can end and can body combination for threedifferent knockout and lifter plate combinations. As shown, forcombinations A and B which use a standard rise knockout and soft riseknockout respectively, a sufficient clamping load is applied for aportion of the transition period and then at about an angle of 6 or 9degrees the clamping load decreases substantially. However, forcombination C which includes a chuck-knockout assembly utilizing atleast some of the features described herein, an adequate clamping loadis applied for at least 70% of the transition zone, preferably at least85% of the transition zone, and even more preferably at least 100% ofthe transition zone. As shown, the clamping load for combination C issufficient for the entire transition zone. Preferably, for thecommercial 12 ounce aluminum beverage cans, the load is between 15 and100 lbf, more preferably the load is between 30 and 38 lbf, and evenmore preferably the about 35 lbf. By applying a load that is sufficientto the can end and can body combination, certain seamers may be operatedat higher speeds with less damage occurring to the can end and/or canbody. Sufficient load for other applications may be chosen according tothe present disclosure based on parameters particular to theapplication.

Other embodiments of a chuck-knockout assembly that can improve thelocating of the can end are envisioned. For example, the improvedlocation may be achieved by locating off of another feature of the endsuch as off of the rivet or some other feature of the can end.

Furthermore, the chuck-knockout assembly may include structures to helpreduce or help create vacuum forces. For example a chuck-knockoutassembly that utilizes such a feature is shown in FIG. 7. As shown, achuck-knockout assembly 12 b includes a chuck body 200 having anaperture 208 formed in the lower body of the chuck-knockout assembly. Avacuum manifold may be in communication with aperture 208 such that thevacuum may be controlled. The vacuum may be employed and the can end maybe located via the vacuum through aperture 208. It should be understoodthat the vacuum force may also be used with chuck-knockout assembly 12a. Alternatively vent hole 208 may be adapted to release trapped airwhen the chuck-knockout assembly 12 b contacts the can end. By allowingair to escape vacuum created by the trapped air will be diminished tothereby make it easier to release the can after the seaming operation iscomplete.

The figures illustrate assemblies 12 a and 12 b employed with an endshown in U.S. Pat. No. 6,065,634. The present invention is not limitedto use with this particular can end. For example, the present inventionencompasses employing the apparatus and methods described herein withthe ends shown in U.S. Pat. Nos. 6,702,142, 6,516,968 and 7,350,392 ortheir commercial embodiments. The disclosures of each of these patentsare incorporated herein in their entireties. Moreover, the presentinvention is not limited to use with beverage containers. The particularconfiguration of the chuck-knockout assembly for these and other endswill be clear to persons familiar with these other can endconfigurations. For example, the second drive surface may include acurved portion that drives in or proximate to a knee or junction betweencan end chuck wall portions in circumstances in which the end chuck wallis a multiple-part chuck wall.

The foregoing description is provided for the purpose of explanation andis not to be construed as limiting the invention. While the inventionhas been described with reference to preferred embodiments or preferredmethods, it is understood that the words which have been used herein arewords of description and illustration, rather than words of limitation.Furthermore, although the invention has been described herein withreference to particular structure, methods, and embodiments, theinvention is not intended to be limited to the particulars disclosedherein, as the invention extends to all structures, methods and usesthat are within the scope of the appended claims. Those skilled in therelevant art, having the benefit of the teachings of this specification,may effect numerous modifications to the invention as described herein,and changes can be made without departing from the scope and spirit ofthe invention as defined by the appended claims. Furthermore, anyfeatures of one described embodiment can be applicable to the otherembodiments described herein.

1. A chuck-knockout assembly for seaming a can end onto a can body toform a seamed container, the chuck-knockout assembly comprising: anupper chuck body including a first drive surface that at least partiallydefines a seaming surface for contacting a portion of the can end duringseaming and against which a seaming force is applied; and a lower chuckbody that is longitudinally moveable relative to the upper chuck bodyand includes a second drive surface that (i) is located outboard of aperiphery of a center panel of the can end, (ii) is capable of locatingthe can end prior to seaming, (iii) is capable of maintaining the canend during seaming, and (iv) is capable of contacting the can end todisengage the can end from the chuck-knockout assembly.
 2. The assemblyof claim 1, wherein the first drive surface and the second drive surfacetogether define the seaming surface during seaming of the container. 3.The assembly of claim 1, wherein the first drive surface isapproximately vertical in cross-section.
 4. The assembly of claim 1,wherein the second drive surface is conical.
 5. The assembly of claim 1,wherein the second drive surface has a curved portion that is capable ofdriving proximate a knee or juncture formed in a chuck wall of the canend.
 6. The assembly of claim 1, wherein a portion of the second drivesurface is located within a countersink of the can end during seamingand disengagement of the container.
 7. The assembly of claim 1, whereinthe can end further comprises a tear panel, and the lower chuck body isconfigured to be devoid of contact with the tear panel during seamingand disengagement of the container.
 8. The assembly of claim 1 whereinthe lower chuck body is concentric to the upper chuck body.
 9. Theassembly of claim 1, wherein the lower chuck body is cam-actuated. 10.The assembly of claim 9, wherein the cam actuation maintains a positiveload during a transition zone.
 11. The assembly of claim 1, wherein theseaming is for forming a double seam.
 12. The assembly of claim 1,wherein the lower chuck body and the upper chuck body define respectiveinner and outer mating surfaces, and the lower chuck body is configuredto have a seaming position and a knockout position relative to the upperchuck body, the seaming position being where the respective inner andouter mating surfaces are disposed proximate to each other, and theknockout position being where the respective inner and outer matingsurfaces are disposed spaced apart from each other.
 13. A seaming systemfor seaming a container including a can end and a can body, the seamingsystem comprising: a chuck-knockout assembly including an upper chuckbody and a lower chuck body, the upper chuck body including a firstdrive surface, and being rotatably coupled to a seaming machine frame,the lower chuck body including a second drive surface, and beinglongitudinally moveable relative to the upper chuck body; and first andsecond seaming rolls configured to form a seam between the can end andthe can body, wherein (i) the first drive surface and the second drivesurface define a seaming surface when the seam is being formed, and (ii)the second drive surface contacts an outer periphery of the can end todisengage the container from the chuck-knockout assembly.
 14. The systemof claim 13, wherein the second drive surface is conical.
 15. The systemof claim 13, wherein a portion of the second drive surface is locatedwithin a countersink of the can end during seaming and disengagement ofthe container.
 16. The system of claim 13, wherein the can end furthercomprises a tear panel, and the lower chuck body is configured to bedevoid of contact with the tear panel during seaming and disengagementof the container.
 17. The system of claim 13, wherein the lower chuckbody is cam actuated.
 18. The system of claim 13, wherein the seconddrive surface is configured to engage a portion of a wall of the canend.
 19. A method of seaming a can end onto a can body to form acontainer, the method comprising: providing a chuck-knockout assemblycomprising an upper chuck body and a lower chuck body; locating a canend from an infeed mechanism onto the chuck-knockout assembly such thata second drive surface of the lower chuck body is in contact with aperiphery of the can end; seaming the can end to a can body to form acontainer while the second drive surface is in contact with theperiphery of the can end; and disengaging the container from thechuck-knockout assembly by moving the lower chuck body longitudinallyrelative to the upper chuck body, the lower chuck body moving from aseaming position to a knockout position, wherein the second drivesurface is in contact with the periphery of the can end as the lowerchuck body is moving to the knockout position.
 20. The method of claim19, wherein a first drive surface of the upper chuck body and the seconddrive surface of the lower chuck body together define a seaming surfacewhen the lower chuck body is in the seaming position.
 21. The method ofclaim 19, wherein the chuck-knockout assembly is in the knockoutposition during the locating step.
 22. The method of claim 19, whereinat least a portion of the second drive surface is disposed within acountersink of the can end during the seaming and disengaging steps. 23.The method of claim 19, wherein the seaming surface extends along a wallof the can end.
 24. The method of claim 19, wherein the can end furtherincludes a tear panel, and the lower chuck body is devoid of contactwith the tear panel during the seaming and disengaging steps.
 25. Achuck-knockout assembly for seaming a can end onto a can body to form aseamed container, the chuck-knockout assembly comprising: a chuck bodyincluding an aperture and a first drive surface that at least partiallydefines a seaming surface for contacting a portion of the can end duringseaming and against which a seaming force is applied; wherein a vacuumforce applied through the aperture locates the can end onto the chuckbody prior to seaming and holds the can end during seaming.
 26. A methodof seaming a can end onto a can body to form a container, the methodcomprising: positioning the can end on top of the can body; lifting thecan body and can end combination with a lifter plate; locating the canend with a chuck-knockout assembly such that the can body and can endcombination is between the lifter plate and the chuck-knockout assembly;maintaining a load that is between 15 and 100 lbf on the can body andcan end combination for at least 70% of the transition zone; seaming thecan end onto the can body during a first seaming operation.
 27. Themethod of claim 26 wherein the chuck-knockout assembly further comprisesa lower chuck body and the can end is located by the lower chuck bodysuch that a second drive surface of the lower chuck body is in contactwith a periphery of the can end.
 28. The method of claim 27 furthercomprising translating the lower chuck body into a seaming positionafter the can end has been located by the lower chuck body, wherein afirst drive surface of the upper chuck body and the second drive surfaceof the lower chuck body together at least partially define a seamingsurface when the lower chuck body is in the seaming position.
 29. Themethod of claim 27 further comprising translating the lower chuck bodyinto a knockout position before the can end is located by the lowerchuck body.
 30. The method of claim 26 wherein the load is maintainedbetween about 30 lbf and about 38 lbf.
 31. The method of claim 26wherein the load is maintained at about 35 lbf.
 32. The method of claim26 wherein the load is maintained for at least 85% of the transitionzone.
 33. The method of claim 26 wherein the load is maintained at leastuntil the can body and can end have engaged an upper chuck body of thechuck-knockout assembly.